How Well It Works

Antibiotics are effective for most UTIs. You should start to feel better within 1 to 2 days after starting antibiotics. If your symptoms get worse or you don't feel better by the third day, call your doctor.

It is important to take all of the antibiotics your doctor has prescribed. Most people begin to feel better soon after they begin the medicine. But if you stop taking the medicine as soon as you feel better, the infection may return.

When taken as preventive therapy, antibiotics also reduce the number of recurrent UTIs. But studies show that this kind of treatment is short-acting. When you stop taking an antibiotic, you are likely to get another UTI.1

Side Effects

All medicines have side effects. But many people don't feel the side effects, or they are able to deal with them. Ask your pharmacist about the side effects of each medicine you take. Side effects are also listed in the information that comes with your medicine.

Here are some important things to think about:

Usually the benefits of the medicine are more important than any minor side effects.

Side effects may go away after you take the medicine for a while.

If side effects still bother you and you wonder if you should keep taking the medicine, call your doctor. He or she may be able to lower your dose or change your medicine. Do not suddenly quit taking your medicine unless your doctor tells you to.

Callor other emergency services right away if you have:

Trouble breathing.

Swelling of your face, lips, tongue, or throat.

Call your doctor right away if you have signs of an infection that is getting worse, such as:

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

Antacids containing magnesium or aluminum and iron or zinc supplements should be taken at least 6 hours before or 2 hours after taking ciprofloxacin or levofloxacin.

Most of these antibiotics can make your skin more sensitive to the sun.

Stay out of the sun, if possible.

Wear long pants, long-sleeved shirts, and hats, if possible.

Use sunscreen with an SPF that your doctor recommends.

If your doctor prescribes antibiotics, ask whether there are any potential drug interactions you should be aware of. For instance, antibiotics can also change the way the anticoagulant (blood thinner) warfarin (Coumadin) works so that you bleed too easily.

Taking medicine

Medicine is one of the many tools your doctor has to treat a health problem. Taking medicine as your doctor suggests will improve your health and may prevent future problems. If you don't take your medicines properly, you may be putting your health (and perhaps your life) at risk.

There are many reasons why people have trouble taking their medicine. But in most cases, there is something you can do. For suggestions on how to work around common problems, see the topic Taking Medicines as Prescribed.

Be sure to take all of the medicine your doctor gives you. Do this even if you feel better. If you do not take all of your medicine as prescribed, the infection may return. Not taking the full course of antibiotics also encourages the development of bacteria that are resistant to antibiotics. This makes antibiotics less effective. And it makes bacterial infections harder to treat.

Advice for women

Fosfomycin and nitrofurantoin

If you are pregnant, breast-feeding, or planning to get pregnant, do not use any medicines unless your doctor tells you to. Some medicines can harm your baby. This includes prescription and over-the-counter medicines, vitamins, herbs, and supplements. And make sure that all your doctors know that you are pregnant, breast-feeding, or planning to get pregnant.

Ciprofloxacin, levofloxacin, and sulfamethoxazole with trimethoprim

Do not use this medicine if you are pregnant, breast-feeding, or planning to get pregnant. If you need to use this medicine, talk to your doctor about how you can prevent pregnancy.

Checkups

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.